🛠 Free Online Developer Tools
Essential developer tools for formatting, encoding, decoding, generating, and validating data. JSON formatter, Base64 encoder, UUID generator, regex tester, hash generator, and 20+ more tools - all running in your browser with zero latency.
28 free tools - no signup required
JSON Formatter & Validator
Format, validate, and beautify JSON data online
Base64 Encoder/Decoder
Encode and decode Base64 strings online
UUID Generator
Generate random UUIDs (v4) and other UUID versions online
URL Encoder/Decoder
Encode and decode URLs and query parameters online
Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes online
Regex Tester
Test and debug regular expressions with real-time matching and explanation
Color Picker & Converter
Pick colors and convert between HEX, RGB, HSL, and CMYK formats
Cron Expression Builder
Build and understand cron expressions with a visual editor
JWT Decoder
Decode and inspect JSON Web Tokens (JWT) online
Markdown Preview
Write and preview Markdown with live rendering
CSS Gradient Generator
Create beautiful CSS gradients with a visual editor and copy the code
HTML Entity Encoder/Decoder
Encode and decode HTML entities and special characters
Lorem Ipsum Generator
Generate placeholder text in paragraphs, sentences, or words
Word & Character Counter
Count words, characters, sentences, and paragraphs in your text
Diff Checker
Compare two texts and see the differences highlighted
SQL Formatter
Format and beautify SQL queries with proper indentation
YAML to JSON Converter
Convert between YAML and JSON formats instantly
Unix Timestamp Converter
Convert between Unix timestamps and human-readable dates
CSS Minifier
Minify CSS code to reduce file size and improve load times
HTML Formatter
Format and beautify HTML code with proper indentation
Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal
JSON to CSV Converter
Convert JSON arrays to CSV format and download as a file
Chmod Calculator
Calculate Linux file permissions in numeric and symbolic notation
Color Palette Generator
Generate beautiful color palettes from a base color for your designs
HTTP Status Code Reference
Complete reference of HTTP status codes with descriptions, examples, and troubleshooting tips
User Agent Parser
Parse and analyze browser user agent strings. Detect browser, OS, and device information.
Color Contrast Checker (WCAG)
Check color contrast ratios for WCAG 2.2 AA and AAA accessibility compliance. ADA Title II deadline: April 24, 2026.
NewJSON to TypeScript Converter
Convert JSON objects to TypeScript interfaces and types instantly
NewFrequently Asked Questions
Are these tools safe for sensitive data?▼
Yes. All developer tools process data entirely in your browser using JavaScript. Nothing is sent to any server. This makes them safe for API keys, tokens, and production data.
Do these work offline?▼
Most developer tools work offline once the page is loaded, since they run entirely in your browser. Bookmark your most-used tools for quick access.